U.S. patent number 5,802,641 [Application Number 08/813,708] was granted by the patent office on 1998-09-08 for leg holder system for simultaneous positioning in the abduction and lithotomy dimensions.
This patent grant is currently assigned to Amatech Corporation. Invention is credited to Kip Van Steenburg.
United States Patent |
5,802,641 |
Van Steenburg |
September 8, 1998 |
Leg holder system for simultaneous positioning in the abduction and
lithotomy dimensions
Abstract
A leg holder system for simultaneously positioning in the
abduction and lithotomy dimensions including a support device for
supporting a leg cradle; a clamping device for mounting the
proximate end of the support device to a mounting device having a
first axis and selectively clamping and releasing motion of the
support device about the first axis and about a second axis
transverse to the first axis. An actuator device for actuating the
clamp to selectively clamp and release simultaneously the support
device and the mounting device; and an operator device remote from
the clamping device and actuator device for operating the actuator
device to enable the support device to move simultaneously about
the first and second axis in both the lithotomy and abduction
dimensions.
Inventors: |
Van Steenburg; Kip (Sudbury,
MA) |
Assignee: |
Amatech Corporation (Acton,
MA)
|
Family
ID: |
25213140 |
Appl.
No.: |
08/813,708 |
Filed: |
March 7, 1997 |
Current U.S.
Class: |
5/648; 5/602;
5/624; 5/649 |
Current CPC
Class: |
A61G
13/0009 (20130101); A61G 13/12 (20130101); A61G
13/101 (20130101); A61G 13/125 (20130101); A61G
13/1245 (20130101) |
Current International
Class: |
A61G
13/00 (20060101); A61G 13/12 (20060101); A61G
013/12 () |
Field of
Search: |
;5/602,624,648,649,650,651 |
References Cited
[Referenced By]
U.S. Patent Documents
Other References
Brouchure of O.R. Direct Surgical Table Accessories (Aug. 1996).
.
Advertisement of Allen Medical Systems..
|
Primary Examiner: Trettel; Michael F.
Attorney, Agent or Firm: Iandiorio & Teska
Claims
What is claimed is:
1. A leg holder system for simultaneous positioning in an abduction
dimension and a lithotomy dimension comprising:
a support device, having a longitudinal axis, for supporting a leg
cradle;
a clamping device for mounting a proximate end of said support
device to a mounting device having a first axis transverse to said
longitudinal axis and selectively simultaneously clamping and
releasing motion of said support device about said first axis and
about a second axis transverse to both said first axis and said
longitudinal axis, said support device fixed in said clamping
device from rotation about said longitudinal axis;
an actuator device for actuating said clamping device to
simultaneously selectively clamp and release said support device
and said mounting device; and
an operator device remote from said clamping device and said
actuator device for operating said actuator device to enable said
support device to move jointly about both said first and said
second axes in the abduction and lithotomy dimensions.
2. The leg holder system of claim 1 in which said clamping device
includes a pair of pressure blocks, a first recess for receiving
said mounting device and a second recess for receiving said support
device.
3. The leg holder system of claim 2 in which said clamping device
includes a biasing device for biasing said blocks to normally
produce friction between said recesses and their respective
mounting and support devices to clamp them in position.
4. The leg holder system of claim 1 in which said actuator device
includes an actuator rod extending with said support device.
5. The leg holder system of claim 4 in which said support device
includes a bore and said actuator rod is disposed in said bore.
6. The leg holder system of claim 4 in which said actuator device
includes a camming device fixed to said actuator rod and a follower
device disposed in said clamping device and responsive to said
camming device for opposing said biasing device to simultaneously
decrease the friction force on said support device and on said
mounting device to release the clamping device in both axes.
7. The leg holder system of claim 1 in which said operator device
includes a handle for both operating said actuator device to
remotely release and secure said clamping device to said support
device and said mounting device and to position said support device
in the abduction and lithotomy dimensions.
8. The leg holder system of claim 1 in which said support device
includes a resilient device for counterbalancing the weight borne
by said support device.
9. The leg holder system of claim 6 in which said operator device
includes a handle for both operating said actuator device to
remotely release and secure said clamping device to said support
device and said mounting device and to position said support device
in the abduction and lithotomy dimensions.
10. The leg holder system of claim 9 in which the axis of said
handle is coincident with the axis of said actuator rod for
independent actuation of said clamp device and motion of said
support device in the lithotomy dimension.
11. The leg holder system of claim 7 in which said handle includes
a rotatable sleeve.
12. The leg holder system of claim 1 in which said support device
includes a cradle bracket for mounting a leg cradle spaced from
said longitudinal axis of said support means.
13. The leg holder system of claim 6 in which said actuator device
includes a limiter device for arresting movement of said camming
device before its highest position to enable said biasing device to
back-drive said camming device when said operator device is
released and automatically re-establish the clamping friction
between said recesses and said support and mounting devices.
Description
FIELD OF INVENTION
This invention relates to an improved leg holder system and more
particularly to such a system in which adjustment in both the
lithotomy and abduction dimensions can be made simultaneously with
a single action.
BACKGROUND OF INVENTION
In recent years many newer surgical procedures have required
interoperative positioning of patients legs. Until recently such
positioning typically required adjusting the leg holder's mounting
clamp located on the surgical table siderail, beneath the sterile
drape. This raised concerns about possible violation of the sterile
field and it limited the performance of such adjustments to
non-sterile personnel. Recent attempts to solve this problem
yielded leg holders that could be raised and lowered through the
drapes, however, they have several limitations. First, when
adjusted upwardly they lock by means of a ratchet mechanism; this
mechanism does not prevent further unintended upward movement of
the legs that could result from tilting the patient in the extreme
head down direction "Trendelenburg" or from surgical staff leaning
against the leg holder. Secondly, abduction is predetermined and
cannot be adjusted without accessing the mounting clamp.
SUMMARY OF INVENTION
It is therefore an object of this invention to provide an improved
leg holder system.
It is a further object of this invention to provide such a system
with which both the lithotomy and abductions for a leg holder can
be adjusted with a single action with one hand.
It is a further object of this invention to provide such a system
which permits adjustment without violating the sterile field.
It is a further object of this invention to provide such a system
which prevents further inadvertent upward movement even when the
patient is tilted in the extreme head down or Trendelenburg
direction.
It is a further object of this invention to provide such a system
which when locked prevents movement in all directions.
It is a further object of this invention to provide such a system
which permits a full abduction adjustment range throughout the full
lithotomy range.
It is a further object of this invention to provide such a system
which the clamps are normally locked and must be activated for
release.
It is a further object of this invention to provide such a system
which release of the actuation of the clamps causes them to default
to the locked condition.
It is a further object of this invention to provide such a system
in which the clamps are remotely operable.
It is a further object of this invention to provide such a system
in which the clamping operation is accomplished through the same
instrumentality as the re-positioning of the leg holders.
It is a further object of this invention to provide such a system
in which the leg holders are counterbalanced for reducing the load
encountered by the user with a patient in place.
It is a further object of this invention to provide such a system
in which the operation of the clamping means can be accomplished
with the same action as the repositioning of the leg holders or can
be decoupled for independent operation.
This invention results from the realization that a truly simple,
fail-safe leg holder system which enables simultaneous positioning
in the abduction and lithotomy dimensions with a single action
outside the sterile field can be effected using an actuator that is
normally biased to clamp both the leg cradle support device and a
mounting device which have a mutually transverse axes and under
control of a remote operator simultaneously releases the clamping
force in both devices to enable movement of the support device
about both axes for repositioning in both the abduction and
lithotomy dimensions.
This invention features a leg holder system for simultaneous
positioning in the abduction and lithotomy dimensions. There is a
support device for supporting a leg cradle and a clamping device
for mounting the proximate end of the support device to a mounting
device having a first axis and selectively clamping and releasing
motion of the support device about the first axis and about a
second axis transverse to the first axis. An actuator device
actuates the clamp to selectively clamp and release simultaneously
the support device and the mounting device. An operator device
remote from the clamping device and actuator device operates the
actuator device to enable the support device to move simultaneously
about both the first and second axes in the abduction and lithotomy
dimensions.
In a preferred embodiment the clamping device may include a pair of
pressure blocks a first recess for receiving the mounting device
and a second recess for receiving a support device. The clamping
device may include a device for biasing the blocks to normally
produce friction between the recesses and their respective mounting
and support devices to clamp them in position. The actuator device
may include an actuator rod extending with a support device. The
support device may include a bore and the actuator rod may be
disposed in the bore. The actuator device may include a camming
device fixed to the actuator rod and a follower device disposed in
the clamping device and responsive to the camming device for
opposing the biasing device to simultaneously decrease the friction
force on the support device and on the mounting device to release
the clamping device in both axes. The operator device may include a
handle for both operating the actuator device to remotely release
and secure the clamping device to the support device and the
mounting device and to position the support device in the abduction
and lithotomy dimensions. The support device may include a
resilient device for counterbalancing the weight of the leg holder.
The axis of the handle may be coincident with the axis with the
actuator rod for independent actuation of the clamping device and
motion of the support device in the lithotomy and abduction
dimensions. The handle may include a rotatable sleeve. The support
device may include a leg cradle bracket for mounting a leg cradle
spaced from the axis of the support means. The actuator device may
include a limiter device for arresting movement of the camming
device before its highest position to enable the biasing device to
back-drive the camming device when the operator device is released
and automatically reestablish the clamping function between the
recesses and the support and mounting devices.
DISCLOSURE OF PREFERRED EMBODIMENT
Other objects, features and advantages will occur to those skilled
in the art from the following description of a preferred embodiment
and the accompanying drawings, in which:
FIG. 1 is a detailed sectional view of a leg holder system with
portions broken away and foreshortened of a leg holder system
according to this invention;
FIG. 2 is a view similar to FIG. 1, with the support device rotated
90.degree.;
FIG. 3 is an exploded view of the leg holder system shown in FIGS.
1 and 2;
FIG. 4 is a pair of leg holder systems according to this invention
as shown in FIGS. 1, 2 and 3 installed on an x-ray table with leg
cradles and leg cradle clamps installed and employing gas cylinder
lift assistance devices;
FIG. 5 is a view similar to FIG. 4 with the leg cradles
repositioned with greater abduction and lesser lithotomy; and
FIG. 6 is a view similar to FIG. 4 with the leg cradles
repositioned with greater lithotomy and lesser abduction.
There is shown in FIG. 1, leg holder system 10 according to this
invention which enables simultaneous positioning in the abduction
and lithotomy dimensions. Leg holder system 10 includes support
device 12 for supporting a leg cradle not shown in FIG. 1, but seen
in FIGS. 4, 5, and 6. System 10 also includes a clamping device 14,
actuator device 16, and an operator device, handle 18. Support
device 12 includes a hollow tube 20 which has its proximal end 22
located in clamping device 14 and its distal end 24 at handle 18.
Limiter device 26 shown more completely in FIG. 3, is mounted at
the distal end 24 of hollow tube 20. Clamping device 14 includes a
clamp housing 30 having a recess 32 which receives and clamps a
mounting device such as pivot post 34 extending from an x-ray
table. Clamp housing 30 is rotatable about axis 36 of pivot post 34
which allows motion in the abduction dimension indicated by arrow
35.
Clamp housing 30 also includes a bore 38 which receives pressure
blocks 40 and 42. Pressure block 40 has a bore 44 through it which
receives the body 46 of pressure block 42. The enlarged tapered
head 48 of pressure block 40 fits in the enlarged tapered bore 50
of clamp housing 30. Enlarged tapered head 52 of pressure block 42
fits in an enlarged tapered bore 54 of clamp housing 30. The distal
end 56 of pressure block 42 includes threads 58 which mate with
threads 60 on locking nut 62. The enlarged head 64 of locking nut
62 engages one of two oppositely facing Belleville washers 66 and
68 located in recess 69. Thus, when locking nut 62 is tightened
down on pressure block 42 it compresses the Belleville washers 66
and 68. This causes the tapered portions 48 and 52 of pressure
blocks 40 and 42 the force of the Belleville washers to be drawn
tightly inwardly against the tapered surfaces 50 and 54 of clamp
housing 30. This wedging effect insures a good tight clamping force
which brings clamp housing together by narrowing gap 70 and thereby
tightening recess 32 about pivot post 34 and simultaneously wedging
pressure blocks 42 and 40 tightly in the tapered recesses 50 and
54, respectively, so that they are held against rotation in the
lithotomy dimension about their central axis 72 as shown by arrow
74.
Thus, in the normal condition locking nut 62 is tightened down
sufficiently to compress Belleville washers 66 and 68 so that a
clamping force is applied to prevent rotation 74 about axis 72 in
the lithotomy dimension and prevent rotation 35 about axis 36 in
the abduction dimension. Release of both of these clamping forces
in both dimensions is accomplished simultaneously by rotating
handle 18 about axis 80 as indicated by arrow 82. This rotation
causes actuator rod 84 to rotate along with actuator member 86
which is fixed by pin 88 to rotate with rod 84. Pressure block 42
includes a bore 75 which is larger than but coaxially aligned with
a similar bore 76 in pressure block 40. The proximal end 22 of tube
20 of support device 12 passes through bores 75 and 76 and is fixed
or force fitted to bore 76 so that when handle 18 and tube 20 of
support device 12 are rotated up out of the paper as indicated by
arrow 77 the entire pressure block assembly including pressure
blocks 40 and 42 is rotated with tube 20.
Actuator member 16 includes two bearing portions 90 and 92 which
receive needle bearings 94 and 96 that enable rod 84 to rotate
smoothly within tube 20. Bearing 96 is supported in journal 98
fitted in the end of tube 20. Between bearing portions 90 and 92 is
eccentric portion 100 which also supports a needle bearing 102.
Riding on needle bearing 102 is follower 104 which extends through
bore 106 in the proximal end 22 of tubing 20. The end 108 of
follower 104 is cylindrically shaped to engage the cylindrical
shape of needle bearing 102. The other end 110 is concave or cup
shaped to engage the spherical tip 112 of set screw 114 which is
threadibly engaged in bore 116 of pressure block 42. Thus, when
handle 82 is rotated about axis 80 it rotates the eccentric portion
100 to bear on follower 104 which in turn exerts an outward force
on set screw 116. As a result there is a force directed along axis
72 which opposes the bias of Belleville washers 66 and 68 thereby
releases the force of pressure blocks 40 and 42 on tapered portions
50 and 54 of clamp housing 30. This allows clamp housing 30 to
spread somewhat thereby increasing the length of gap 70 so that
recess 32 relaxes its grip on pivot post 34 and permits rotation as
indicated by arrow 35 in the abduction direction and simultaneously
permits pressure blocks 40 and 42 to rotate in the tapered recesses
50 and 54 so that actuator rod 84 and tube 20 of support device 12
can be rotated in a direction out of or into the paper as indicated
by arrow 77.
Thus with one action, the rotation of handle 18 about axis 80, the
clamp releases its grip to allow rotation about both axis 36 and
axis 72 to provide simultaneous repositioning in the abduction and
lithotomy dimensions. When the handle is released the force of
Belleville washers 66 and 68 back-rotate the eccentric, snapping
the handle to the normal position and allowing the Belleville
washer to reinstate the clamping force on both axes. Covers 120 and
122 may be installed to cover the heads of pressure blocks 40 and
42, respectively.
The rotation of support device 12 in the direction of arrow 77,
FIG. 1, is shown in FIG. 2, where upon the rotation of handle 18
about axis 80 and the application of eccentric 100 to counteract
the clamping force of Belleville washers 66 and 68, the entire
support device 12 including tube 20 and the actuator rod 84 have
been rotated from the plane of the paper in FIG. 1, to the upright
position where tube 20 and actuator rod 84 are perpendicular to the
plane of the paper in FIG. 2.
The rotational symmetry as well as rotational action may be better
understood with reference to the exploded three dimensional view in
FIG. 3. Also shown in FIG. 3 is collar 130 which is held to the end
of tube 20 by means of set screw 132 and the limiter collar 26a on
the other end of tube 20 which is held there by means of set screws
140 and 142. A circumferential slot 144 which extends less than all
the way around the circumference of limiter collar 26a receives
limiter pin 146 fixed to rotate with actuator rod 84. A pair of
bushings 148 and 150 are mounted on either end of limiter pin 146
after it is mounted in hole 152 of actuator rod 84 to provide for a
smoother rotation within slot 144. It is limiter pin 146 in
conjunction with the limited extent of slot 144 that arrests the
rotation of actuator rod 84 before it reaches top dead center on
the cam so that upon release by the human operator of handle 18 the
handle and actuator rod 84 snap back to the position where they do
not oppose the force of Belleville washer 66 and 68 and so the
Belleville washers reinstate the fail-safe clamping force on both
axes. Handle 18 is rotatably mounted on pin 160 which is mounted
for rotation about axis 85 on pin 162. Pin 62 includes a groove 164
that allows it and handle 160 to rotate about axis 85 but which
engages with spring loaded balls 166 and 168 that prevent the
handle 160 and pin 162 from being withdrawn from the hollow end 170
of actuator rod 84.
Although thus far the system can be shown as actuated by mechanical
device namely, the action of eccentric 100. This is not a necessary
limitation of the invention, for example, any device may be
substituted for eccentric 100 which will exert the opposing force
on follower 104 or a similar device to release the action of
Belleville washers 66 and 68 on the pressure blocks and clamp
pressure blocks 40 and 42 and clamp housing 30. For example, a
hydraulic piston could be installed in place of eccentric 100
driven through hydraulic lines by a foot pedal, for example, which
would be remote from the device and external to the sterile drapes.
Similarly an electrical device having a movable armature could be
used in the same fashion or even a piezo electric crystal or
similar device when only small mechanical movements are
required.
Typically, in use, two such systems 10a and 10b are used in
conjunction with an x-ray table 180, FIG. 4. X-ray table 180
includes two rails 182 and 184 on which slide blocks 186 can be
slid into and out of the plane of the paper and tightened at a
desired location by handles 190 and 192. Pivot posts 34a and 34b
extend upward from clamps 186 and 188 into recesses 32a and 32b,
not shown, of clamp housings 30a and 30b. Mounted on each support
device 20a and 20b are leg cradles (leg holders) 200 and 202
pivotally mounted on axes 204 and 206 which are spaced from the
axes 80a and 80b of tubes 20a and 20b by support shafts 208 and 210
which are supported in clamps 212 and 214 that are clamped into
position on tubes 20a and 20b by handles 216 and 218. The lifting
of the weight of this system including cradles 200 and 202 and the
legs of the patient may be assisted by means of springs or gas
cylinders or other devices as symbolically indicated by gas
cylinders 220 and 222 mounted to support tubes 20a and 20b by
clamps 224 and 226 and mounted to pivot posts 34a and 34b by clamps
228 and 230.
In FIG. 4, cradles 200 and 202 are in a midrange position with
respect to the lithotomy and abduction dimensions. By simply
gripping handles 18a and 18b and rotating them in the direction of
arrows 230 and 232 the eccentric members are engaged opposing the
Belleville washer force and freeing up and releasing the clamping
action on both axes 32a and 32b and axes 72a and 72b. Now by simply
moving the handles downwardly as indicated by arrows 240 and 242
the cradles 200 and 202, FIG. 5, can be moved to a lower position
in the lithotomy dimension and may be spread farther apart in the
abduction dimension as shown in FIG. 5, or alternatively the same
motion of handles 18a and 18b in FIG. 4, which releases the clamp
in both dimensions. After the operation of both of them which
releases them in both dimensions the handles 18a and 18b can be
moved upwardly to increase the position in the lithotomy dimension
and reduce somewhat the position in the abduction dimension as
shown in FIG. 6. In each case upon the accidental or intentional
release of the handles 18a and 18b the limiter device allows the
Belleville washers to snap the handles and the actuator rods and
the eccentric out of position so that the Belleville washers, once
more in a fail-safe mode, apply the clamping force in both
dimensions.
Although specific features of this invention are shown in some
drawings and not others, this is for convenience only as each
feature may be combined with any or all of the other features in
accordance with the invention.
Other embodiments will occur to those skilled in the art and are
within the following claims:
* * * * *